The MOPAGRAS computer program
calculates magneto-optically parametrically amplified field envelopes of
forward and backward travelling wave components inside a Bragg grating of
sinusoidal spatial distribution of the refractive index.

The program essentially wraps the calculating core provided by the
mopagrat() Fortran-77 routine into a stand-alone executable program,
in which command-line parsing for parameters and output files is supported,
as well as including for the possibility of specifying different scan
parameters, that is to say, specifying different variables to be varied
in investigating for example optimization or phase matching properties of
the parametric process.

The zgaussj(a,n,np,b,m,mp) routine
solves linear systems of equations Ax = B by
Gauss-Jordan elimination, using an algorithm similar to
Numerical Recipes in Fortran 77, but modified to handle
complex-valued systems.